Fluid pressure mechanism



Oct. 22, 1935. J. KUCHAR I FLUID PRESSURE MECHNISM 7 Sheets-Sheet l Filed May 6, 1932 f ay ye fedaj J. .KUCHAR FLUID PRESSURE MECHANISM Oct. 22, 1935.

.Filed May 6, 1932- I 7 Sheets-Sheet 2 J. KUCHAR FLUID PRESSURE MECHANISM Filed May 6, 1932 '7 Sheets-Sheet 5 Oct. 22, 1935. J. KUCHAR 2,018,269

FLUID PRESSURE MECHANISM Filed May 6, 1932 7 Sheets-Sheet 4 Oct. 22, 1935- J. KUCHAR FLUID PRESSURE MECHANISM '7 Sheets-Sheet 5 Filed May 6, 1952 lllll.\

0t.22,- 1935. 'J KU HA 2,018,269

FLUID PRESSURE MECHANISM Filed May 6, 1932 7 Sheets- Sheet 6" 061522 1935. J. KUCHAR 2,018,269

1 FLLiID PRESSURE MECHANISM Filed May 6, '1932 7 Sheets-Sheet '7 I L/Qs ephJZQCa'r Patented Oct. 22, 1935 UNITED STATES PATENT OFFICE FLUID PRESSURE MECHANISM Joseph Kuchar, Chicago, Ill., assignor to Athey Truss Wheel 00., Chicago, 111., a corporation of Illinois Application May 6, 1932, Serial No. 609,603

14 Claims.

scribed in connection with one particular purpose, that is the'control of door opening and closing mechanisms on a trailer from a tractor. It will, however, be understood that the invention is capable of innumerable applications and that it is not intended to limit the invention to the particular purpose described. By way of example the invention is described in connection with a liquid pressuresystem. It will however be understood that the invention is not limited thereto since it is capable of embodiment in forms employing air or gases as the pressure fluid.

In a hydraulic apparatus of this type the fluid is delivered under pressure, for example from a pump, and is diverted by means of valves to desired cylinders or other hydraulic devices which are actuated. When the cylinder or-other device is full the liquid can no longer be supplied. Since the liquid is not compressible means must be provided for by-passing the supply, since the operator cannot be relied upon to stop the pump at the exact time in order to prevent injury to the system.

One of the objects of the invention is to provide a fluid pressure system comprising a bypass which is automatically opened andiwhich' presents substantially no resistance to the pump.

A further object of the invention is to provide a device of the character described, comprising a pair of by-passes for the pump, one of which is adapted to open automatically upon the attainment of a predetermined pressure, the

other being adapted to be opened manually and the first by-pass being adapted to be closed automatically when the second by-pass is opened.-

A further object of the invention is to provide a pump and valve unit for a device of the character described which is simple in operation, easy to construct and is durable and efllcient in operation.

Other objectaadvantages and capabilities will appear from-the following description of a pre- Fig. 2 is an elevational view showing the pump and valve unit, together with the control'means therefor in elevation and on a substantially larger scale;

Fig. 3 is a rear view of the pump and valve unit;

Fig. 4 is a sectional view therethrough taken on the line 4-4 of Fig. 3;

Fig. 5 is a sectional detail view taken on the line 5-5 of Fig. 4;

Fig. 6 is a further sectional view taken on the line G6 of Fig. 4;

Fig. 7 is a sectional view taken on the line 1-1 of Fig. 4;

Fig. 8 is a sectional view through the line 8-8 as a bottom dump wagon supported on tread laying wheels 22. Itis not considered necessary to go into detail regarding the construction of the wagon 2|. It is suflicient to indicate that it comprises bottom doors 23 which are adapted to open downwardly when a latch is released which may be effected by supplying pressure fluid to a cylinder 24 by means of a conduit 25. These doors may in turn be elevated to closed position by means of a cylinder 26 when pressure fluid is supplied thereto through conduit 21. The two cylinders 24 and 26 are, of course, merely examples of cylinders or other pressure actuated means which may be controlled in the manner hereinafter described. For example, a train of trailers may be hitched to the tractor 20 and a ram on each trailer may be actuated from the pump and valve unit.

The pump and valve unit may suitably be mounted on the rear end of the tractor 2 0 and may comprise a tank 28 which serves as a reservoir for pressure liquid such as oil. The tank 28 is supported by brackets '29 which are mounted on the face plate 30 which carries the clutch 5 housing 3|. The pump, which is designated generally by thereference numeral 32 is secured to the clutch housing 3| and the valve by-pass unit, which is designated generally by the reference numeral 33, is mounted upon the upper end; of

' in an annular groove 18 in the stem 16.

the pump housing. The three elements 3 I, 32 and 33 are best seen in Fig. 4. The combined unit including the tank 28 is secured upon the rear end of the tractor 28 by means of the face plate 38 as'shown in Figs. 1 and 2.

The tank 28 is connected by means of a pipe 34 with the inlet side of the pump 32, which may suitably be a. gear pump comprising gears 35 and 36. The outlet side of the pump connects with a chamber 31 which is adapted to discharge through openings 38 and 39 in a flange 48 upon which the valve unit 33 is mounted. The gears 35 and 3B are driven by the spindle 4I upon which the gear 35 is keyed. This spindle projects into the clutch housing 3I and its end is splined so as to carry the clutch element 42. The clutch element 42 is adapted to be slid longitudinally of the shaft 4I so as to engage the clutch element 43 carried by the drive shaft 44 which may be driven in any 1 suitable way, for example from the transmission of the tractor. v

The clutch member 42 carries a slip ring 45 which is adapted to be actuated by the slotted ends 01 arms 46 rigidly carried by a spindle 41,

i which is pivotally mounted in one side of the clutch housing 3i. The upper end of the spindle 41 projects out of the housing and rigidly carries anarm 48. To the arm 48 is pivotally connected a rod 49 which is actuated in a manner hereinafter described in order to connect and disconnect the pump drive. The clutch housing 3| is provided with an inlet 58 whereby lubricant may be introduced into the housing and a drain opening whereby the housing can be drained. The opening 38 in the flange 48 is closed by a ball valve 52 under the action of a spring 53 which is housed within the valve by-pass unit. The pressure fluid supplied by the pump is adapted to open the valve 52 and the pressure liquid is discharged into ducts 54 and 55, which are best shown in Fig. '7 and alsoin the diagrammatic Figures to 18. These ducts 54 and 55 terminate in a' conical seat in which is located the valve plug 56. The valve plug 56 is provided with cut away portions 51, 58 and 59 whereby various ducts, including the ducts 54 and 55, may be put into communication in various ways to control the operation of the desired cylinders. These ducts will now be referred to. Adjacent the terminations or the ducts 54 and 55 and above same, ducts 68 and BI terminate in cooperative relation to the valve plug 56. The ducts 88 and Bi communicate with outlet conduits 62 and 63 respectively. These outlet conduits are connected by means of flexible hoses 64 and 65 with the pressure lines 25 and 21 which actuatethe cylinders 24 and 26 respectively. Between and above the ducts 68 and GI the valve plug 56 communicates with a low pressure chamber 66 which communicates through a duct 81 with a low pressure chamber 68, which is open to the valve plug 56 between the high pressure ducts 54 and 55. The low pressure chambers 66 and 68 communicate through a discharge outlet 69 with the tank 28.

Theplug'56 is held in its conical seat by means 01' a spring 18 which abuts against a cover plate H of the valve by-pass unit 33. The cover plate 1I carries a boss 12 which receives a stem 13 of the plug 56. The outer end of the stem 13 is provided with a slot 14 which is adapted to receive a rib carried at the inner end of a stem 16. Th stem 16 is received in the boss 12 and is held therein by means of a screw 11 which is received At this outer end the stem 16 carries a plate 19 and an arm 88. As shown in Fig. 2, the plate 19 is provided around its edge with cam surfaces which are adapted to be engaged by a cam roller 8| carried on alever 82 which is pivotally mounted adjacent its center on the cover plate 1I. At its 8 lower end the lever 82 is pivotally connected to a collar 83 which is rigidly mounted in adjustable position upon the rod 49. The rod 49 extends beyond the collar 83 and a spring 84 is mounted on the rod and abuts against the collar 83 and against 10 an abutment guide 85 which may be integral with the cover plate 1I. It will readily be understood that the spring 84 normally tends to force the clutch members 42 and 43 out of engagement so as to terminate the drive or the pump 32. In 18 the position of the valve plate 19 the drive of the pump is interrupted. When, however, the valve plate 19 is rotated in clockwise direction, the roller 8i rides up a cam rise immediately the clutch members are moved into engagement.

The movement of the valve plug 56 and plate 19 is controlled by a hand lever 86 located convenient to the driver oi! the tractor. The hand lever 86 is provided with a spring detent 81 which is adapted to engage notches 9, I8, II, I2 and I3 on a rigid sector. The reference numerals I8, II, I2 and I3 given to the notches correspond with Figs. 10, 11,

12 and 13, which illustrate the corresponding positions of the valve plug 56. When the hand lever 86 occupies these various positions the hand lever 86 is connected by a. link 89 which is pivotally connected to a short lever 98 pivotally mounted on one of the brackets 29. One end of the lever 98 is connected by a link 9| to the arm 88 so that for each movement of the hand lever 88 a corresponding rotation of the valve plug 56 occurs.

The opening 39 registers with an opening 92 which opens into a side of ahorizontal, cylindrical bore 93 into which is inserted a sleeve 94 provided with. opposite openings 95 and 96. The opening 96 communicates through a port 91 with the low pressure chamber 66. The sleeve 94 receives a hollow piston valve 98 which is adapted to be pressed inwardly by a spring 99 which abuts against a cover plate 1I, so as to interrupt the passage between the high pressure port 39 of the pump and the low pressure chamber 66 of the valve by-pass unit 33. The inner end of the piston valve 98 is of conical formation for a purpose which will hereinafter be described. .5

The port 92 communicates with a small duct I8I which communicates with the inner end of a bore I82 which is also provided with aliner I83. A piston valve I84 is located within the liner I83 and is adapted to be pressed inwardly by a spring I85. The pressure on the spring I 85 can be adjusted by means of a cap I88 which is threaded into the outer threaded end of the bore I82. The ducts I81 and I88 extend into the bore I82 at opposite sides thereof. These ducts may be drilled simultaneously since they are in alignment and the outer end of the duct I81 may be closed bya plug I89. The duct I81 communicates through a duct II8 with the inner end of the bore 93. The duct' I88 communicates with aduct III which is shown in dot-and-dash lines in Fig. 4 to extend from. the exterior of the casting into the low pressure chamber 66 of the valve by-pass unit 33. The outer end of the duct III is closed by a plug H2. The sleeve I83 is provided with openings I I3 and H4 in alignment with the ducts I81 and I88. The opening H3 is substantially longer than the opening I I4 in the longitudinal direction of the sleeve I83. The valve I84 is provided with a peripheral 15 groove H5, which in the normal closed position of the valve I04 is in alignment with the openings H3 and H4 so that it establishes communication between the ducts I01 and I08.

The cover plate H is provided on its inner side with a recess II6 which extends over the sleeve 94 so as to communicate to the inside thereof behind the piston valve 98. The recess II6 also extends over a duct II1 which communicates with the low pressure duct 61. The passageway thus formed enables the fluid back of the piston valve 98 to be displaced during the operation of the device, as will hereinafter appear.

When the hand lever 86 is in position 9, the valve plate 19 is in the position shown in Fig. 2 and the clutch members 42 and 43 are disengaged. When however the hand lever 86 is moved into the position I the lever 82 is swung by the cam surface on the valve plate 19 so as to move the clutch member 42 into engagement with the clutch member 43, thereby starting the pump, it being assumed that the tractor engine is running. This same movement locates the valve plug 56 in the manner shown in Fig. 10, that is the duct is in communication with the low pressure chamber 66 by meanr of the cut out portion 58 and the ducts 55 and 6| are in free communication through the cut out portion 51.

The duct 54 is in free communication with the duct 55 so that the valve is in a completely open or neutral position and circulation effected by the pump is delivered by the duct 55 to the low pressure chamber 66 from whence it returns to the tank 28. through the discharge outlet 69. In other words, the circulation by-passes through the valve 56. When however the hand lever 86 is moved forwardly to position II the valve 56 is rotated into the position shown in Fig. 11. In

this position the high pressure duct 55 is closed and the high pressure duct 54 is put into communication with duct 60, by means of the cut out portion 58. It will readily be seen that the pressure fluid supplied by the pump is now forced through the duct 60 to the cylinder 24,

forcing the cylinder outwardly to accomplish its function, which in the specific instance illustrated, is the unlatching of the doors 23. When the cylinder. 24 is filled, the pressure rises and' the pump must be immediately by-passed in order to save damage to the machine. passing will now be described The pressure on the high pressure side of the pump is communicated through the duct I M to the face of the piston valve I04. When this pressure rises above its normal maximum, which occurs when the cylinder 24 is full, the piston valve I04 is pressed upwardly. as viewed in Figs. 4 and 5, against the action of the spring I05. The-actuating pressure can, of course, be adjusted by adjusting spring I05 by means of the nut I06 or by replacing the spring by another one having the desired strength. When the piston valve I04 is moved upwardly sufliciently the pressure fluid discharged by the pump is admitted through the opening II3. ducts I01 and H0 to the underside of piston valve 98. The upward movement of the piston valve I04 moves the groove II5 past the openings H3 and H4 so that communication between the ducts I01 and I08 is shut off. The 'piston valve 98 is consequently forced to the right as viewed in Fig. 6 until it uncovers the openings 95 and 96. This immediately provides a by-pass between the high pressure discharge chamber 31 of the pump and the low pressure chamber 66, through which the fluid rushes, the flow forcing This by- '3, the piston valve 98 to the right against the action of the spring 99. The fluid back of the piston 98 passes through the recess 11 and duct II1 into low pressure duct 61. The spring 98 is of such strength that the flow of fluid passing through 5 the openings 95 and 96 is able to keep it open. This condition exists until the hand lever 86 is againactuated. If the hand lever 86 is moved into position I2 the valve 56 closes the duct 60 so that the cylinder 24 is maintained full of fluid, which condition is maintained, for'example if the engine is stopped or used for other purposes, for example pumping fluid to other cylinders. by means of another distributing valve similar to 56. When the hand lever 86 is moved into position I2, 15 a by-pass relationship is created between high pressure duct 54 and low pressure duct 68, thereby by-passing the pump while holding the cylinder 24 full of liquid.

When the hand lever 86 is moved to position I3 the high pressure duct 55 is put into communication with duct 6i through the cut out portion 59 so that the cylinder 26 is actuated. At this time the cylinder 24 is permitted to return its fluid through duct 60, and cut out portion 51, to the 25 tank 28.

When the hand lever 86 is moved back to position I2, the cylinder 26 may be maintained full of liquid in the manner above described with reference to cylinder 24. It is to be noted that when 30 the hand lever 86 is further returned to position II the cylinder 26 may return its fluid through duct 6| and cut out portion 51.

The operation of the device will more readily be understood from the following description of typical operation of the embodiment illustrated. Referring to Fig. 1, the doors 23 are closed, the cylinders 26 are full of pressure fluid, the same being maintained therein due to the fact that valve 56 is in the holding position shown in Fig. 12. The cylinder 24 is empty and the latch is closed by a spring associated therewith. The pump is working but is by-passed through out out portion 58 which extends between the high pressure duct 54 and the low pressure duct 68. It is assumed that the loaded wagon is brought to a position where the load is to be dumped. The hand lever 86 is moved into position I I and high pressure fluid is supplied tothe cylinder 24 in the manner described above thus releasing the latch. The weight of the load opens the doors 23 actuating the pistons of the .cylinders 26 so as to return the pressure fluid in the cylinder to the tank 28 through the duct 6|, the same being in communication with the low pressure chamber 66 through the cut out portion 51.

In the ordinary use of the machine the operacor will not actuate the hand lever 86 immediately the cylinder 24 becomes filled. Consequently the pressure builds up the pressure side of the pump and the valve 98 is opened in the manner described above. In order to return the valve 98 to its closed position it is necessary to move the valve 56 into a by-pass position. For example into position I0 or I2; that is the neutral or holding position. In the first case the high pressure duct is in free communication with the low pressure chamber 66 through the cut out portion 51. In the latter case the high pressure duct 54 is in free communication with the low pres- 70 sure chamber 68 through out out portion 59. Whenever either of these by-passes is established the flow through the openings 95 and 96 is diminishedso that its tendency. to maintain the valve 98 open is reduced. The spring 99 consequently is able to close the valve 98. In the present example it is assumedthat the by-pass is established by moving the lever 86 to the position I 2. The load has-now been dumped and it is necessary to close the doors 23. lhis is efiected by moving the hand lever 86 to the position l3 which causes the pump to supply pressure fluid to the cylinder 26 through duct 55, out out portion 59 and duct 6|. When the doors are elevated the latch is operated and holds the doors in position until-the cylinder 24 is again supplied with pressure fluid.

While I have shown a single valve 56 controlling two cylinders 24 and 26, it will be obvious that I may modify this valve 56 and the associated ducts so as to take care of a larger number of cylinders. It will also readily be understood that I may provide a plurality of valves of the same type as 56 so as to multiply the number of cylinders which may be actuated from a single pump. In the latter case the valve 56 may be modified so as to provide a position at which the supply of high pressure fluid may be completely cut off, or an independent valve may be provided so that the supply of pressure fluid to each valve 56 may be turned off or on at will.

Although the invention has been described in connection with specific details of a preferred embodiment thereof, it must be understood that such details are not intended to be limitative of the invention except insofar as set forth in the accompanying claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a by-pass valve adapted to withstand working pressures, means adapted automatically to open said by-pass valve when a predetermined pressure is attained on the pressure side, said by-pass being arranged to permit a flow with substantially no pressure loss and' to keep'open by said flow, a manually operable bypass valve in parallel with the automatic by-pass valve, and means tending to close the automatic by-pass valve, the capacity of the manually operable by-pass being such that its opening reduces the aforesaid flow to a degree insuflicient to keep the first said by-pass valve open.

2. A by-pass ,control for pressure fluid comprising an automatic by-pass valve adapted to withstand working pressures and tending normally to close, means controlled by predetermined pressure adapted to open said by-pass valve, said by-pass valve being arranged to be held open by the by-pass flow therethrough with slight loss of pressure in the by-passing stream, and a by-pass valve in parallel. with the automatic by-pass valve, the means normally tending to close the automatic by-pass valve being such that it is effective to close the same when the second bypass valve is opened and the flow through the first by-pass valve is thereby substantially reduced.

3. A by-pass control for pressure fluid comprising a channel through which the by-pass fluid is adapted to flow, a piston valve adapted to operate transversely to said channel to open and close same, said piston valve being biased so as normally to tend to close, and having an end arranged to be actuated by the by-pass flow so as to remain open, a pressure actuated valve adapted to admit fluid to the underside of the piston to effect the opening of the piston valve when predetermined pressure is attained, a channel in parallel with the first said channel, and an operated valve controlling the second channel, the means member, said member being adapted to be moved 10.-

towards open position by said pressure and being arranged to be maintained open by the bypassing stream without substantial loss of pressure, and a second by-pass iirparallel with the first said by-pass, the by-pass valve member be- 15-;

ing arranged to close when the stream through the first said by-pass is reduced on the opening of the second said by-pass.

5. In combination, a by-pass, a by-pass valve member adapted to close the by-pass, means 20..

adapted to admit pressure fluid to one end of the by-pass valve member when a predetermined pressure is attained on the pressure side of said member, said member being adapted to be moved towards open position by said pressure and its said 25.

end being configured so that the by-passing stream'maintains said member in open position without substantial pressure drop, and a second by-pass in parallel with the first said by-pass, the

by-pass valve member beingiarranged to close 30.:

when the stream through the first said by-pass is reduced on the opening of the second said by pass.

6. A by-pass control for pressure fluid comprising a channel through which the by-pass fluid 5' is adapted to flow, a piston valve adapted to operate transversely to said channel to open and close same, a spring tending to maintain said piston valve closed, said piston valve having an end arranged to be actuated by the by-pass flow so 40 as to remain open when fluid is passing therethrough, a pressure actuated valve adapted to admit fluid to the underside of the piston to effect the opening of the piston valve when predetermined pressure is attained, a channel in par- 45 allel with the first said channel, and an operated valve controlling the second said channel, the spring being arranged to effect the closing of the piston valve when said flow is substantially reduced by the opening of the operated valve.

7. A by-pass control for pressure fluid compris ing a channel through which the by-pass fluid is adapted to flow, a piston valve adapted to 0perate transversely to said channel to open and close same, a. spring tendingto maintain said 55 piston valve closed, said piston valve having a coned end adapted to be actuated by the by-pass flow so as to remain open when fluid is passing therethrough, a pressure actuated valve adapted to admit fluid to the underside of the piston to 60 effect the opening of the piston valve when predetermined pressure is attained, a channel in parallel with the first said channel, and an operated valve controlling the second said channel. the spring being arranged to effect the closing of the piston valve when said flow is substantially reduced by the opening of the operated valve.

8. In combination, a fluid pump, an automatic by-pass valve therefor, an operated distributing valve adapted to establish a by-pass in parallel with said automatic by-pass valve, said automatic by-pass valve being adapted to permit fluid to pass without substantial drop of pressure, automatic means adapted to permit the bypass valve to open when a predetermined pres- 15 sure is attained, and means, tending to close said automatic by-pass valve and operative to close said valve when the flow of liquid therethrough is substantially reduced.

9. In combination, a fluid pump, an automatic by-pass valve therefor, an operated distributing valve adapted to establish a by-pass in parallel with said automatic by-pass valve, said automatic by-pass valve being arranged to permit fluid to pass without substantial drop of pressure, a spring pressed valve adapted to admit fluid to open said automatic by-pass valve when a predetermined pressure is attained, and a spring tending to close said automatic by-pass valve and operative to close said valve when the flow of liquid therethrough is substantially reduced.

10. In combination, a fluid pump, an automatic by-pass valve therefor, an operated distributing valve adapted to establish a by-pass in parallel with said automatic by-pass valve, a spring pressed valve adapted to admit fluid to open said automatic by-pass valve when a predetermined pressure is attained, and a spring tending to close said automatic by-pass valve, said automatic bypass valve being configured so that substantial flow maintains the valve open against the spring, the spring closing the valve when the flow is substantially reduced.

11. In combination, a fluid pump, an automatic by-pass valve therefor, a pressure operated device adapted to be supplied with pressure fluid from said pump, an operated distributing valve adapted to open and close connection between said pump and device arid adapted to open a bypass in parallel with the first said by-pass valve, and pressure controlled means adapted toadmit fluid to open said automatic by-pass valve when a predetermined pressure is attained, said by-pass valve being arranged to be maintained open by a substantial flow and being adapted to close when the flow is reduced.

12. In combination, a fluid pump, an automatic by-pass valve therefor, a pressure operated device adapted to be supplied with pressure fluid from said pump, an operated distributing valve adapted to open and close connection between the pressure device and the high pressure side of said pump and between the pressure device and the low pressure side of said pump and to bypass'from the high to the low pressure side of the pump, and pressure controlledmeans adapted to admit fluid to open said automatic by-pass valve when-a predetermined pressure is attained, said by-pass valve being arranged to be maintained open by a substantial flow and being adapted to close when the flow is reduced.

13. In combination, a fluid pump, an automatic by-pass valve therefor, a plurality of pressure operated devices adapted to be supplied with pressure fluid from said pump, an operated distributing valve adapted to open and close connection between each of said devices and said pump and adapted to open a by-pass in parallel with the first said by-pass valve, and pressure controlled means adapted to admit fluid to open 'said automatic by-pass valve when a predetermined pressure is attained, said by-pass valve being arranged to be maintained open by a substantial flow and being adapted to close when the flow is reduced.

14. In combination, a fluid pump, an automatic by-pass valve therefor, a plurality of pressure operated devices adapted to be supplied with pressure fluid from said pump, an operated distributing valve adapted to open and close connection between the pressure devices and the high pressure side of said pump and between the pressure devices and the low pressure side of said pump, and to by-pass from the high to the low pressure side of said pump, and pressure controlled means adapted to admit fluid to open said automatic by-pass valve when a predetermined pressure is attained, said by-pass valve being arranged to be maintained open by a substantial flow and being adapted to close when the flow is reduced.

JOSEPH KUCHAR. 

